US1919918A - Molding and pressing method and apparatus - Google Patents

Description

y 1933- J. N. WHITEHOUSE MOLDING AND PRESSING METHOD AND APPARATUS Filed July 5, 1929 FIG: I.

FIE l Jon A! Mv/ rzuousc,

i of the heat p tions xmay be made without departing'froin l w Fig: 11 is a side elevation."

i Patented July 25," 1933 it Jenn mgwrnrnnousn or NnwYonx, NQYQ, nssrenonrro sAnIrE conronn'i'ion, or

BURLINGTON, NEW JERS Y, A conrorm'rronwor NEW JERSEY nonnmennn rnnssine'rrsrrnon Ann lirrenn'rus Application filed July 5, 192-9. s r aino. 376K184. T

i Myiinvention relates tonew andiniproved methods and apparatushfor molding; or

shaping articles 3 or materials which become plastic when heated,'such as hard rubber venienceasheat plasticmaterial.

d A principal ohjectis tojformcloserand/or speciallywsha ed ends on cylindrical tubes liistic material, asufor exa nple fountainpens,.eto. fs 1 1 'A-rnore particulariobject is to expedite and otherwiselimprovepresent.processes by on abling the article; to. .be quickly removed fromuthe forming. mechanism; and th s 1s aocornplished principally by the prov sion "and roperhuse of avdevlce 1n the nature of a. forming.capor thimble. r Since, only: 1 one end 3 portion of the tube remains unheated and hardfland pressing tion to the desired fforrn. Provision is made,

otherwise for theproduction of .various special Tend formations including closed ends, or open;ends '(asjwhenthe closure of the end is to be completed .by insertion of "a plug), and in either case to prodnce' varis ous externally tapered or rounded end for-n pp p p p T n 1 .I11n er plunger? may beoperated m an suitable way, asby a rodlpassingthrough mations. n

p 1- The? characteristics adi antagesiof invention are further sufiiciently explained in] connection1with the following detaildescription of the acco npanying drawing,

which shows L representative embodiments. After consideringlthese examples, skilled,

persons will understandthat' many ariathe? principles disclosed and I contemplate that n "Fig. IVis a front elevation 1 of a press,

embodying the apparatus of the invention in one form. L

and celluloid, hereafter referred tofor con- Fig. V 11 is a similar view requires reshaping, the inyention provides a for softening, byheating,;,onlyysuch end portion, :While the remainder of the :tube" orgshaping the heated and plasticendflpor by the useof proper forrning thimhles, and

Fig avertical section of the heatin" ;and pressing elements.

l ig. IV shows another operativeposlt on ing cap, in sectiom cleviceofthe same kind. 1

articledn: one form. i

"PATENT OFFICE,

plasticmaterial; ready for the shaping op; jerations. p Fig. VI shows a tubular former, or form- 1 i Fig. VIII is a. side View of the completed Fig. X shows a-modified forming cap and lower plunger.

, -Tl1e press (Figs. I and II) iincludesayoke framelljbase 2, arm 3, tubular upper plung er s arranged toreciprocate therein, hand )wheel ,5, rackfinand a,gear n0t shown) for.

operating plunger 4:, a central u per plunge er or ejector 7reciprocahlewwith1nthe tubu larplun'ger, :and a lower. plunger" or mandrel .11 monntedon, the base, or one plate 10 thereon,E-as bydprloviding the mandrel base,- or in plate 10. i r i i a f yAn electric heating coil 13 with nproper circuit connections and control is located abontthe tubular plunger.

slots 15 in the tubular plunger.

forming caps orfthimble-LIQ FigS. II I forming cap is shaped to produce the desired externalforrh.

. 'Fig. V shows a heat-plastic tube of with n dowel 8- inserted in ahole 9 inthe and VIjI-(and also shown in other forms'in :FigSUVI -y IX and X) is placed in, the generally tapered lowerp'ortion of the hollow hard rubber,'celluloid, or other material-ca;-

pahle of beingllsoftened by heatandpressed or moldedloy. the present apparatus and method.

If of celluloid, the tube may have a solid or homogeneous wall structure, or it may be of the type which is produced by winding a celluloid sheet, with a solvent, about a mandrel, and in such. cases may have any of various distinctive or decorative patterns, or opal'escent or other attractive appearance due to translucence, etc. ,A tube 16 is placed about the mandrellll, resting on the press base, or plate thereon. The hollow plunger 4 with forming cap 12 in place as shown, is then brought down to engage the lower portion of the cap about the upper part of tube 16. The plunger is heated to desired temperature. by coil 13,-- and this heat is applied through cap 12 to the upper portion of the tube 16, which-is made plastic, while the lower portion of' the tube is'cool and hard, so that there is no risk of deformation of the tube, except such portion as is to be reshaped, as would be likely to occur if the entire tube were heated and softened. In the continued downward movement of the plunger and cap,the material of the tube end is forced to flow upward, and: as the plunger and cap 12 reach final position (Fig. IV) the plastic inaterial-fills'the space between the mandrel and the cap, forming a more orless tapered, closed and rounded end l7, with interior form corresponding to the shape of the mandrel. I

To permit escape of entrapped air the top of the thimble 12 may have a small venthole 18; and inorder to insure filling of the space between the mandrel and cap, and correct and uniform shaping of. inner and outer surface of the molded article, down ward movement ofthe thimble may be con tinueduntil a certain excess amount ofpthe plastic'is extruded through the-vent, as at Fig--X. This vent hole, and the extrusion of-material, may be omitted in some cases.

Plunger 4 is then. withdrawn upward, leaving the forming thimble on the tube end; in apreferred mode of operation, the thimble is retained byfriction in thetapered 'bore of the plunger, and thus tube 16 is drawn upward away from mandrel 11, and finallythe thimble is ejected from the plunger by action of ejector 7 the thimble remaining in position about the plastic tube end until the latter cools and hardens in proper form. The thimble is then removed, and :the projecting port-ion or tit 20 produced by extrusion is trimmed off and the tube otherwise finished as desired. Ejection of the thimble may be efiected by hand actuation of rod 14 connected by the ejecting plunger 7, or in the upward movement of plunger 4, the rod 14 may engage afixed abutment,'as at 3 Fig. I, thus positively: freeing the thimble from its socket in plunger 4.

The forming thimble 12 and its use in the manner indicated, are therefore important elements of the invention, since the thimble remains in position on the formed tube during hardening, to preserve its shape, and also permitting the formed tube to be quickly removed from the press, and immediate reuse of the press for another shaping operation; whereas in previous practice, as when the inner surface of a heated form ing element similar to plunger 4 is engaged directly with the heat plastic tube, after the forming action the plunger must remain in position while it and the formed tube cool sufficiently to permit separation and this evidently involves great waste 0 heat and time, since the press is kept practically idle during the cooling or sett1ng" period.

The invention'procedure as described also avoids deformation of the molded tube end by premature withdrawal of a forming plunger such as 4 from-direct contact therewith. Figs. VII and IX show differently shaped forming caps, the cap 12 of Fig. IX'being adapted for the production ofthe article of Fig. VIII, which has a relatively long, tapered, closed end portion '22.

In some cases, it is desired to form the tube with a more-or-less externally rounded or tapered contour,but open-ended, and to close the end opening with a plug ofthe same material as that of the tube: celluloid, in case of a celluloid tube. It is also desirable to produce a thickened tube. wall at the formed end, and at the same time avoid a difiiojulty experienced in attempting to round off plain tubes, which results in a wall section of reduced thickness and a thin edge, at the end which is to be plugged.

For the stated purposes as shown in Fig.

III, mandrel 11' has inserted in its upper I end a plug 11, diametered to produce in the tube end a hole of proper size to receive the closure plug to be inserted therein. Mandrel 11 may also have a tapered, or

' other s'uitable formation below plug 11 to provide the desired internal tube-form and upper tube wall section. Forming thimble 12 has in this case a hole 12? in its top, diametered to fit with close clearance about plug 11. The plug may have a slight draft (upwardtaper) to facilitate withi finished as fdesired, "and (the closure'l plug inserted. l

Evidently ingof onlyfia portion [of a heat plastic article orftubeto, render itgmoldable, molding it without possibility ot deformation of the remainder of thearticle, and in the use of i a forming tlnmble whlch rema ns upon the is Ij uclalm riwll a i l d r llA methodof molding or pressingfia article and preserves its shape while setA tin article-from the press.

heat-plasticarticle,comprising heating only alportionfiofthei'article torender it plastic, and while plasticyF-pressing I it' to desired altered shape by application; of a forming thimble, relieving the *form-ing pressure, re;

taining thethimble on the article until the material thereof has 'set, and removing the thimble from the article. i

2. Amethod of pressing or shaping a cause the material tov flow and produce a 3. A method of molding or pressing a heat-plastic article, Comprising applying a hollow member about'one' end portion of the article, and applying an interposed forming device to such end portion, applying pressure and applying and maintaining heat to. cause the material" to flow and as sume a desired form. r

4; Amethod of pressing or shaping a tube of heat-plastic material, comprising placng e up av a vd e pp y n 1a "pressure and-applying and maintaining hollow member aboutlone end portion of the tube, and applying aninterposed forming device :to such end portion, applying heatto oausethe material to flow andas sume a desired form.

purposes described, comprising an article support, a heating element movable into position to heat said article, means for shaping the a heated portion-r df the article,

saidmeans including a forming thimble,

6. Shaping or pressing apparatus for pup-1 poses described, comprising an article support, a heating element movable into position to heat said article, and means for shaping the heated portion of the am le, said means includinga-separ'able forming cap within said heating element. a 7. Shaping or pressing apparatus forpur the forming capsand other parts of the apparatuswmay :be varied for the production of variously shaped articles, with'or without closed 1ends,*a principal teature of theinvention' consisting i'n the heat;

g, and also permits quick removal ofthe opening.

a movable to position about anend portion and'aforming cap removably located withinfthe plungergqy I i a 8. Sh pingorupressingapparatus for I poses described; comprising base, a mandrelthereon for supporting a tubular heatplastic article, a substantially hollow plunger' mova-ble: to position about an end portion ofthe" article, means for heating the plunger,

of the article, means for heating the plunger,

and a' forming cap removably located With- 7 in the plunger, ,andyan ejecting plunger movable withinthe hollow plunger to engage the formingcap, H

9.; Shap'ng or pressing apparatus for pur- 3 poses described, comprising abase a mandrelgthereon for supporting ztubular heatplastic article,a substantially" hollow plunger movable to position about anend-porti of:=the"article, means for. heating the plung er, and forming cap removab-ly {located within the plunger, the heating means con sisting of an electric heating coil externally located on the hollow plunger.

10. Shapingor pressing apparatus for mandrel thereon for supporting a tubular portion ofthe article, means for heating the plunger, and a forming capiremovably loplug in the plunger, and a forming cap removably located within the plunger, anda plug'in the heat-plastic article, a substantially hollow: plunger movable to position about an end upper end of the mandrel, the formlng cap 7 having an end aperture to accommodate the plug whereby to produce an open ended tube formation. a i

a 12. The combination with a press including a mandrel, and a heating plunger, ofa

heating plungerl a 13. The combination with apressincluding a mandrel, and a heatingplungeniof a d forming thimble removably located in the 5. Shaping or pressing, apparatus for 7 forming thimble "removably located in the heating plunger, the thimblehaving a top g ing a mandrel, and a heating plungenof a forming-thimbleremovably located in the heating plunger, and an ejector within the I plunger to actupon the'thimble.

15. The combination with a press including a mandrel, and a heating plunger, of a forming-thimble removably located in and held'byffrictionalcontact with the heating plunger, and a plug at the top ,of the man 90 purposes described, comprising a base, a

drel, the thimble having a top opening to receive the plug.

I. 16. The combination with a press including a mandrel, and a heating plunger, of a forming thimble removably located in the heating plunger, the thimble having a top opening, and an ejector within .theplunger to act upon the thimble."

- 17. The combination with a press including amandrel, and a heating plunger, of a forming thimble removably located in the heating plunger, and a plug at the top of the mandrel, the thimble having a top opening to receive the plug, and an ejector within the plunger .to act upon the thimble.

18. A method'of pressing or shaping a tube of heat plastic material comprising applying pressure and applying and maintaining heat through a forming thimble'to cause the material of the tube to flow and produce asubstantially closed end formation, relieving the pressure and; the heat, retaining the thimble on the article until the material thereof has set, and removing the thimble from the article.

19. The method of closing one end of a tube formed of curedpyroxylin compound which comprises, softening one end of the tube, and in a single operation compressing the softened end between a mandrel, and a die having a socket shaped to correspond to thevdesired external shape of the finished cap.

20. The method of closing one end of a tube formed of cured pyroxylin compound which comprises softening one end of the tube, and in a single operation compressing the softened end between a mandrel and a die having a socket shaped to correspond to the external shape of the finished cap, and simultaneously forcing surplus material of the softened tube through a vent in the die.

.JOHN N.WHITEHOU'SE.

Images